kvm: always start in paused state

Currently kvm starts in a frozen state if cpu pinning is set.
This is useful for other purposes as well (eg. ballooning before the
instance uses the memory), so we move the functionality out of the cpu
pinning code.

Note that before the "continue" command was executed in a finally after
trying to set the cpu pinning. This didn't help if anything else in the
function failed before that, though. As such we just move it out, as
anyway a failure above will cause an exception, so the user will know
their start command hasn't succeeded anyway.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

diff --git a/lib/hypervisor/hv_kvm.py b/lib/hypervisor/hv_kvm.py
index 4cec09a..e39d430 100644 (file)
--- a/lib/hypervisor/hv_kvm.py
+++ b/lib/hypervisor/hv_kvm.py
@@ -1419,6 +1419,8 @@ class KVMHypervisor(hv_base.BaseHypervisor):
     # instance is not already paused and if we are not going to accept a
     # migrating instance. In the latter case, pausing is not needed.
     start_kvm_paused = not (_KVM_START_PAUSED_FLAG in kvm_cmd) and not incoming
+    if start_kvm_paused:
+      kvm_cmd.extend([_KVM_START_PAUSED_FLAG])
 
     # Note: CPU pinning is using up_hvp since changes take effect
     # during instance startup anyway, and to avoid problems when soft
@@ -1426,8 +1428,6 @@ class KVMHypervisor(hv_base.BaseHypervisor):
     cpu_pinning = False
     if up_hvp.get(constants.HV_CPU_MASK, None):
       cpu_pinning = True
-      if start_kvm_paused:
-        kvm_cmd.extend([_KVM_START_PAUSED_FLAG])
 
     if security_model == constants.HT_SM_POOL:
       ss = ssconf.SimpleStore()
@@ -1484,16 +1484,13 @@ class KVMHypervisor(hv_base.BaseHypervisor):
 
     # If requested, set CPU affinity and resume instance execution
     if cpu_pinning:
-      try:
-        self._ExecuteCpuAffinity(instance.name, up_hvp[constants.HV_CPU_MASK])
-      finally:
-        if start_kvm_paused:
-          # To control CPU pinning, the VM was started frozen, so we need
-          # to resume its execution, but only if freezing was not
-          # explicitly requested.
-          # Note: this is done even when an exception occurred so the VM
-          # is not unintentionally frozen.
-          self._CallMonitorCommand(instance.name, self._CONT_CMD)
+      self._ExecuteCpuAffinity(instance.name, up_hvp[constants.HV_CPU_MASK])
+
+    if start_kvm_paused:
+      # To control CPU pinning, ballooning, and vnc/spice passwords the VM was
+      # started in a frozen state. If freezing was not explicitely requested
+      # resume the vm status.
+      self._CallMonitorCommand(instance.name, self._CONT_CMD)
 
   def StartInstance(self, instance, block_devices, startup_paused):
     """Start an instance.